Pollination is carried out mainly by bumble bees of the genus
Bombus including B. pascuorum, B. lucorum, B. hortorum, and B. lapidarius (Dunn 1977;
Valentine 1978; Prowse and Goodridge 2000). In addition, Apis mellifera is a regular
visitor, while wasps of the family Vespidae also visit later in the season

I would need to do some work tracking it down but there have been two or three papers published showing that in riparian sites, the balsam does lead to an increase in bank erosion.

Also

Quote:

2. There is evidence to suggest that in woodland, native species are released from suppression upon removal of I. glandulifera as demonstrated by the significant increase in species diversity particularly in the increased number of species occurring at low cover in the removal treatments.

My main issue with the balsam is with regards to water courses however and the specific problem of suppression of species that have roots that help prevent erosion.

I may have more to say on this issue once I have fully read the paper and looked up some of the other literature on the subject. Will also send the link to a friend who works for the local Wildlife Trust.

Well I sent the above to my local wildlife trust and received this reply-SIGH

Quote:

Himalayan Balsam is an invasive non-native species which dominates riverbanks and other wet areas to the severe detriment of native species. It also dies back in winter leaving bare earth prone to erosion causing siltation problems further downstream. We are committed to working to eradicate this species in North Wales and will soon be taking on a project officer to tackle this and other non-native species on the Dee Catchment. Whilst it provides pollen and nectar for bees there are many other plants that can do this that do not also pose a serious threat to native species and wetland habitats.

Further to my post above I then received this email from my local (friendly)wildlife trust

Quote:

Plants around at this time of year include knapweeds, hawkweeds, buddleia (a less invasive non-native), heather, lavender, scabious, and many garden plants.
Admittedly, intensive farming has resulted in the decline of 98% of our wildflower meadows since 1945, but Himalayan Balsam is not the answer. I’m afraid you are not going to convince me that HB is a good plant to have around as I have seen the problems it causes. It is incredibly destructive to native wildlife and should be eradicated despite the fact that bees for obvious reasons like it.
Unfortunately some beekeepers have helped spread it over the years and this has got to stop.

I have yet to see any evidence that it is 'incredibly destructive to native wildlife'. I would want a lot more detail and some hard evidence before I could agree with any such statement, which is contrary to what I see happening - other plants thriving alongside it, due to its late emergence and late flowering season.

And how can they defend buddleia and condemn HB? No consistency there!

And an update from my local (friendly)wildlife trust officer on this subject

Quote:

In the early stages or under some conditions other plants can co-exist with HB, but in most cases, especially after a while, a monoculture of HB is formed and the problems begin.

We have already eradicated HB from the upper Alyn Valley so it is possible to do so with concerted effort and landowner agreement. As the seeds are not wind-carried it tends to spread up along catchments but not between them.

Re: buddleia, it’s nowhere near as invasive as HB and does not create bare earth in the winter as it is a long-lived perennial. so does not need to be removed. Not everyone agrees with me on this however!

I would like to put forward some facts about Himalayan balsam and provide the reasons why it is of such concern to conservationist. I work as an Invasive species officer for a local Wildlife trust and am also a bee keeper - two things that some may feel is contradictory.

I have worked with invasives for over 12 years and would by no means claim to be an expert but my actions are always based on the facts which I reference with current research and best practice. Incidentally I have kept bees for 6 of those years.

Ok so I will start with why is HB bad. The standard information about HB is generic wherever you look - it increases erosion and decreases biodiversity - but is this corrrect? I will go through the following statement that’s from an earlier post [i]'Himalayan Balsam is an invasive non-native species which dominates riverbanks and other wet areas to the severe detriment of native species. It also dies back in winter leaving bare earth prone to erosion causing siltation problems further downstream.'[/i]

Dominates river banks - true. HB spreads very readily if left unmanaged due to 4 factors 1) large seed production and viability; 2) few natural predators; 3) the ability of the plant to reduce the fitness of the soil thus reducing the viability of native seedlings (pure.rhul.ac.uk/portal/files/4459536/2012Tannerraphd.pdf) and 4) the early germination of the plant can shade out most species of native flora.

Severe detriment of native species - true. As mentioned above the plant has been shown to affect the fitness of the soil. This work has been carried out more recently that the work referred to at the start of this discussion. The exact science around it is still under investigation and does indeed need more research but it is a worrying find in terms of recovery of sites.

Dies back leaving bare soil - true. The plants life cycle means that by now we are looking at the straw like remains of the plant that are very rapidly washed away during floods leaving bare soil. Due to the shallow root system when the plant dies the top few inches of soil become looser and therefore more susceptible to erosion. With reference to the River Dee which is mentioned in a post above a quick google search points out that surface sediments (wash off from banks) are primarily responsible for the siltation of important salmon and trout spawning grounds. I am not claiming HB is responsible for this but its presence on the river will be adding to an already serious problem for the local river wildlife.

Ok, so are invasivs all bad? There are few positives when we look at invasives such as balsam but is one we all know;
Balsam has the highest energy pollen of all European plants - a nice fact but (and there is always a but) what does this mean for wildlife? Well if you think about this in another way we can see - if the HB attracts all the pollinators how many species will not be pollinated as a result? What species of wildflower should have been pollinated at that time? At low levels an invasive plant can actually increase pollination of wildflowers as it draws the pollinators towards new areas but as the plant dominates the pollination of the surviving wildflowers dramatically reduces (ref: biological invasions journal).

So what does this mean for bee keepers (myself included I remind you all). Well the BBKA issued a statement regarding HB in July 2011. For those of you who have not read it then the gist of it is 'don’t let it spread into the countryside, if you plant it in your garden you must deal with it responsibly and this is how to keep it under control'. I am all for responsible management of any plant (even the dreaded Japanese Knotweed can be responsibly managed to not invade all and sundry) but this is only feasible if you are able to ensure that you remove the plants before they set seed. The problem with this approach is that by the time the late nectar source is of it greatest benefit the plant has started to set seed so unless you pick off each developing seed pod every few days it’s not really practical or that beneficial. Also, I disagree that the pollen makes nice honey, I find it sickly but that is probably due to my associations with the plant if anything.

So, what does it mean for conscientious bee keepers who keep bees for 2 reasons 1) the love of honey and 2) the love of wildflowers. HB may be the only natural food for your hive at certain times of the year but think about what should be there? Why isn’t it? That is what we should be fighting about. Proper management of road verges for example would provide enough pollen to negate the need for a high energy pollen source; most councils cut road verges too early in the year so there is often no chance for the native plants to produce flowers for pollen or seeds to restock the seed bank; this approach removes a very important source of pollen late in the year and eventually leave verges that are dominated by grasses and successor species such as nettles and brambles. We need to start looking seriously about WHY there isn't enough food about for our bees and start pushing for very simple changes to the management of wild areas that could help solve this problem. Bee keepers are in a prime position to push for these changes.

And finally a word about us fluffy conservationists who don’t understand - we do, we all have to live in the same world with the same issues and we have to reach a solution that benefits that world not us. We have to look after our world and the species in it. Yes HB is a species we should look after but in the Himalayas not in the UK where we have a lot more species to worry about, every one of our native species is here for a reason, they all have an important part to play in our native ecosystems and therefore to lose even one means that we have effectively lost a gear in our engine. We had hives before balsam and produced some of the best honey in the world so let’s get back to that way of thinking guys.

Us conservationists are not against bee keepers (or I would be having serious internal battles), we want to work with you all so that our natural world can be or benefit to us both as the others we share it with. My job involves a lot of time talking to people from different backgrounds who have mixed feelings about invasive species, I can’t solve all of the issues but I can provide the evidence for you to make up your own minds. I would suggest that those of you who would like to do a Google scholar search for HB and its effects and make the decision your selves but please remember to make sure you get the most recent data and that you read ALL the good and bad information.

Ok so that is all I can say at the moment. I hope I have helped you all understand the issues we both face. If any of you would like further information please post questions or just send me a PM.

I forgot to mention - as an Invasives officer i take issue with Buddleja davidii BUT only in the countryside. Buddleja davidii is very invasive in the urban environment leading to issues with built structures and developments. In the wider countryside it is less invasive as it is not as competative as a lot of our natives.

Incidently it is ONLY Buddleja davidii that is invasive, other species suchs as the globi or dwarf varieties are very well behaved.

Unless it starts invading out nature reserves and natural places then you can keep it in your gardens for as long as you like - a word of warning though, keep an eye on any cracks in your brickwork!

Thanks for showing up here and giving us the benefit of your experience. It would be nice to know a little more about you, but that is up to you - we don't insist on personal revelations - although we DO require your location in your profile, please.

However, I must question some of your assertions, based on my observations over a number of years of HB in my area (South Devon). HB grows in patches along the banks of River Dart, especially in the stretch just below the weir above Totnes. There is a considerable quantity of it beside the Teign upstream from Newton Abbot. Until recently, there was an area of woodland at Staverton that had a high density of HB.

Nowhere have I seen any evidence of increased bank erosion. In fact, the roots of HB seem to have been doing a good job of holding the bank together in places on the Teign, especially.

It absolutely and unequivocally does NOT always die back to exposed soil - at least, nowhere I have seen. The patch I keep under observation on the Dart is covered with numerous other species at all times, and right now is green well after all HB has died back. Most of the other species have several months' head start on HB in the spring, as it does not even appear above ground until June in most places, by which time things like Purple loosestrife, cow parsley and so on are a 2-3 feet high. As they flower and decline, HB takes over and comes into flower usually from late August onwards, often continuing right through well into October if the weather is mild.

You ask what does it replace in terms of flowers - I say, practically nothing. I challenge you to name any species of flowering plant that it clearly suppresses or replaces, let alone one that is good forage for bees.

IMO I welcome this plant as being one of the few that brighten up the riverbanks and meadows late in the year and that provide a wide range of pollinators with a valuable, pre-winter boost at a time when there is practically nothing else for them to eat other than ivy - and how much of that do you want in your hives?

I am not calling for a mass planting of HB - it is quite capable of doing that itself - and I recognize that there are places where it needs to be controlled, but in general, it has proven itself wildly popular with bees of all species, as well as butterflies, moths and no doubt other bugs.

Last edited by biobee on Thu Nov 29, 2012 12:02 pm; edited 1 time in total

Sounds like we are saying that this introduced element is OK unless proven harmfull. (sounds a bit familiar that)

I take your point, Mark, but that's not really what I am saying.

A parallel example would be Bombus hypnorum which is recorded as arriving in Britain in 2001.

It has been largely cheered on by the bumblebee people (the same people who say that the honey bee is 'not native' and therefore not a subject for conservation, by the way), yet you could make a case for it 'robbing the food of other bees' if you had a mind to - but nobody does, because it is a furry little bumblebee.

Likewise, you will find people who support the grey squirrel in Britain, despite the enormous amount of damage it does to young trees and the fact that it has displaced the native red squirrel.

I am saying that, given the fact that HB has become naturalized, appears to be more beneficial than not, and would now be massively expensive to eradicate, there may be a case for re-evaluating it rather than mounting a knee-jerk 'hack it down' campaign, based on what seems to me to be shaky evidence.

And that is only my opinion.

And it would be helpful if people who only drop in here to voice their opinions would actually enter into the ensuing discussion, instead of dropping a bomb and disappearing...

I find it strange that you refuse to accept that Himalayan Balsam is an invasive species. An invasive species is defined as "an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health". Many governing bodies and other ecological and environmental authorities have designated Himalayan balsam as an invasive non native species. This would not be done if there was not, and quote, enough research to back that decision up. Furthermore these are the same authorities which have also designated grey squirrels as invasive which you believe without question.
Research is constant and yes more research probably does need to be done on the subject I'm sure, but you have to understand that when someone writes a scientific paper it is not automatically the authority on the subject. I advice reading a minimum of 10 papers on a subject before committing to an opinion.

If you choose to ignore the people who are more informed about the subject and not accept that Himalayan balsam has ecological/ environmental effects then that is your choice. But I would advise that you read more on the subject before trying to sway others to your opinion.

I've not fully read this thread however find the general tone a bit odd, we can't frown on imports of foreign Bees and other species that have no benefit or may cause harm to our bees. yet be suggesting that HB isn't all that bad. As far as I am concerned HB along with Japanese Knot weed and all the other imports in the wild should be eradicated. Obviously I understand that isn't always possible and I will be upset that my bees don't have as good forage. But I'd rather they foraged on native plants.

I've not fully read this thread however find the general tone a bit odd, we can't frown on imports of foreign Bees and other species that have no benefit or may cause harm to our bees. yet be suggesting that HB isn't all that bad.

I don't see that as inconsistent: nobody suggested deliberately importing HB was acceptable, but since it is here and since it thrives in certain habitats and (according to some) does little damage; and considering that it apparently can be controlled by livestock grazing with no detrimental effects; and since it is harmless to humans and pretty much everything else; and since is is demonstrably popular with bees and other insects, who have little else to eat at the time of year when HB is in flower, I'm saying that, on balance, it is hard to summon up any enthusiasm for a campaign to wipe it out - even if such a campaign had the remotest chance of being successful.

I think it would be difficult to justify grazing as a reasonable control measure given that one of the concerns and possibly the most unquestioned problem this plant causes is bank erosion.

Then again, have you seen what “some” fisherman do to river banks to create the perfect swim! I wonder if there is a possibility that the massive increase in angling may be partly responsible for a share of the bank erosion blamed on HB.

It’s a tricky one. From my eyes it does appear to be out-competing nettles on my local stretch of river which are hugely popular for a lot of our native wildlife.

Thought I'd revive this thread, as I've been trying to source some HB seeds - which is proving nigh impossible. Spoke to a one-time Ebay seller who received so many threats from environmentalists that he's decided to opt for a quite life instead.

So - if anyone can assist with some HB seeds, roots, cuttings - anything which can be propagated - I'd be very grateful. For garden planting only.

Incidentally - it appears that the idea of this plant 'escaping' from Victorian gardens to populate the countryside is something of a myth - there have have numerous people (some quite famous) who've been deliberately seeding river banks.

Dusko, it needs damp ground. If your weather is anything like ours, ie very hot and dry this summer, it will struggle unless it is damp/boggy ground and partial shade.

Colin, why not try using" google earth" to check out your local river banks/streams and ditches to find where there are pink areas and then go and collect some seed yourself. They are ripe when you touch the pods and they explode. As above to Dusko, they much prefer damp shaded ground, so if your garden conditions don't suit it, it won't grow. The roots are really shallow, so they need to be surrounded by plants that shade the soil, usually each other but long grass and brambles do a decent job.

I'm not convinced about how palatable they are as my horses won't eat them and I'm inclined to think that cattle trample them rather than graze then as they are easily knocked over and once the stem is damaged, they are finished.

Steve, I'd never have even thought of trying to eat them. Did you eat the leaves or the flowers and did you have them raw in a salad or cooked? Must confess I'm a little wary of eating anything that I don't know for certain is safe since my brother ended up in hospital and neatly died from eating a tiny piece of a plant that he thought was a yam.(He lives in Tenerife) It took months for him to recover.

The bankside above my house is a good mixture of HB, brambles, rosebay willow herb, meadowsweet, cow parsley, reeds, nettles and many other plants as well as grass. I would dispute that the HB degrades the soil in itself, as the amount of organic matter that it puts back onto the surface when it dies back, keeps the earth covered and conditioned. I find that in spring, these areas are carpeted in celandines and there is a canopy of flowering cherry, so plenty thrives in the same ground.
I can see the potential problem along the river banks in the winter, but that doesn't make it all bad and perhaps instead of trying to eradicate it, we should be putting that effort into willow banking the river areas that are prone to erosion. Thereby improving the forage for pollinators instead of trying to diminish it.

I'm no expert though and I haven't read 10 studies on it I'm afraid!
I have lived with the stuff right on my doorstep for the past 40+ years though and I see how many insects benefit from it. I live in the bottom of the valley right next to a stream, so I am also aware of the risks of flooding, but good maintenance of drains, ditches and streams is what I concentrate my efforts on to prevent the worst.

You can eat the flowers raw in salad. Similarly for the seeds, which have a nice nutty taste. The leaves and also the stem are very slightly toxic and so should be boiled or steamed with a change of water which makes them fully safe. Though, I should say, I have eaten the leaves raw with absolutely no ill effects apart from flatulence.

Conserving wild bees

Research suggests that bumble bee boxes have a very low success rate in actually attracting bees into them. We find that if you create an environment where first of all you can attract mice inside, such as a pile of stones, a drystone wall, paving slabs with intentionally made cavities underneath, this will increase the success rate.

Most bumble bee species need a dry space about the size a football, with a narrow entrance tunnel approximately 2cm in diameter and 20 cm long. Most species nest underground along the base of a linear feature such as a hedge or wall. Sites need to be sheltered and out of direct sunlight.